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  Brightness enhancement structure of luminescent assemblyUSPTO Application #: 20070278931Title: Brightness enhancement structure of luminescent assembly Abstract: The present invention relates to a brightness-enhanced light-emitting structure of a luminescent assembly, and more particularly, to a structure capable of enhancing the brightness of a luminescent assembly by directing blue/ultraviolet light of a light-emitting source to shine on a fluorescent/phosphorescent coating so as to excite visible light therefrom in a surface excitation manner. The brightness-enhanced light-emitting structure of a luminescent assembly is comprised of: a blue/ultraviolet light-emitting source having a side thereof being coated with a cover layer; and a light screen disposed outside the light-emitting source, having a primary visible light layer arranged on the inner surface there of at a position opposite to the cover-layer-coated side of the light source; wherein a visible light or white light, being a mixture of visible lights, is emitted from the primary visible light layer in the surface excitation manner as soon as the primary visible light layer is irradiated by the ultraviolet or blue light of the light-emitting source, while the cover layer of the light-emitting source is blocking the harmful ultraviolet light and the same time being excited directly or indirectly to generate another visible light, and thus the brightness of the luminescent assembly is enhanced. (end of abstract)
Agent: Wpat, PC - Annandale, VA, US Inventor: Jenn-Wei Mii USPTO Applicaton #: 20070278931 - Class: 313489 (USPTO) The Patent Description & Claims data below is from USPTO Patent Application 20070278931. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATIONS [0001]This application is a Continuation-In-Part of U.S. Ser. No. 11/443,147, filed on May 31, 2006, now pending, and is hereby incorporated by reference in its entirety. FIELD OF THE INVENTION [0002]The present invention relates to a brightness-enhanced light-emitting structure of a luminescent assembly, and more particularly, to a structure capable of enhancing the brightness of a luminescent assembly by directing blue/ultraviolet light of a light-emitting source to shine on a fluorescent/phosphorescent coating so as to excite visible light therefrom in a surface excitation manner. BACKGROUND OF THE INVENTION [0003]Generally, the brightness of any conventional luminescent apparatus, such as a fluorescent lamp, is dependent upon the luminous intensity of the light source used thereby. As fluorescent lamps are more efficient than incandescent light bulbs of an equivalent brightness since more of the consumed energy is converted to usable light and less is converted to heat, allowing fluorescent lamps to run cooler, most luminescent apparatuses available now adopt fluorescent lamps as their light sources. A fluorescent lamp is substantially a glass tube filled with an inert gas and mercury vapor while the inner surface of the tube is coated with a fluorescent paint made of varying blends of phosphors. When the light is turned on, the electric power heats up the cathode of the fluorescent lamp enough for it to emit electrons. These electrons collide with and ionize inert gas atoms in the tube to form a plasma by a process of impact ionization. As a result of avalanche ionization, the conductivity of the ionized gas rapidly rises, allowing higher currents to flow through the lamp, and thus the mercury is then likewise ionized, causing it to emit light in the ultraviolet (UV) region. The UV light is absorbed by the fluorescent coating, which re-radiates the energy at lower frequencies to emit visible light. The blend of phosphors controls the color of the light, and along with the tube's glass prevents the harmful UV light from escaping. However, the aforesaid fluroscent lamp is disadvantageous in that: [0004](1) As the fluorescent coating is a phosphor film with a specific thickness while the surface of the phosphor film can be easily excited by the ultraviolet light to emit visible light, the intensity of the ultraviolet light is weakening as it is penetrating deeper into the phosphor film so that the visible light generated deep in the phosphor is conceivably fewer than that from the surface of the fluorescent coating. Consequently, the fluorescent coating can be considered to be a light emitting device capable of emitting most light from its surface and lesser light from its interior. That is, visible light created deep inside the fluorescent coating will be weaker than that created at the surface thereof. [0005](2) The fluorescent coating is not a good translucent material and will cause the luminous intensity of the visible light, generated from the surface thereof, to be weakened when it is passing through the fluorescent coating and exiting from the glass tube. That is, the luminous intensity of the visible light is adversely affected by the fluorescent coating. [0006]As a conventional fluorescent lamp 1, shown in FIG. 1A, is a sealed glass tube containing a fluorescent coating 2 coated along the inside of the glass, most of the visible light generated form the inner surface of the fluorescent coating 2 is blocked by the fluorescent coating 2 itself that causes the brightness inside the tube is actually better than that outside the tube, That is, the brightness of the fluorescent lamp 1 is mainly dependent upon those visible light generated from the interior of the fluorescent coating 2 so that the conventional fluorescent lamp is most likely to have poor brightness. In addition, as the visible light, generated form the inner surface of the fluorescent coating 2, passes through the filtering of the fluorescent coating 2 and reaches the glass tube, the remaining visible light is once again being filtered by the glass tube and weakened again. Therefore, the luminous efficacy of most conventional fluorescent lamps is poor since they are suffered from the visible light being filtered by fluorescent coating, as addressed in the description hereinbefore. [0007]Moreover, if only half of the inner surface of the glass tube of a fluorescent lamp 1' is coated by the fluorescent coating 2 while another half of the glass tube is considered to be transparent, as shown in FIG. 1B, the visible light, generated form the surface of the fluorescent coating 2 can be discharged out of the fluorescent lamp 1' directly through the transparent half of the glass tube without being filtered by the fluorescent coating 2, and thus the aforesaid problem of poor brightness caused by the filtering of the fluorescent coating 2 can be avoided. However, as the ultraviolet light can also being discharged directly out of the fluorescent lamp 1' through the transparent half of the glass tube without being filtered by the fluorescent coating 2, it can cause damages to eyes and skins in spite of most of the ultraviolet light is filtered out by the glass tube. Therefore, the forgoing half-coated fluorescent lamp 1' is not recommended. Apart from the aforesaid reasoning of not recommending, the portion of the ultraviolet light, being directly discharged out of the fluorescent lamp 1' without hitting on the fluorescent coating 2, is wasted since it is not used for exciting usable visible light. Therefore, it is conceivable that the brightness of the half-coated fluorescent lamp 1' can be greatly improve if the portion of the wasted ultraviolet light can be salvaged and made good use of. [0008]Referring to FIG. 1A and FIG. 1B and quantifying the brightness of the visible light generated from the surface of the fluorescent coating 2 to be 1.0 unit, illustrated in FIG. 1B, the brightness measured from the outside of the fluorescent lamp 1, that is, the totality of the visible light generated from the interior of the fluorescent coating 2 and those remaining visible light generated form the inner surface of the fluorescent coating 2 and filtered by the fluorescent coating 2, is about 0.9 unit, while the brightness measured from the outside the coated-half of the fluorescent lamp 1' is only 0.47 unit since it is suffered from the aforesaid waste of ultraviolet light. Hence, although most conventional luminescent assemblies, employing the fluorescent lamp 1 of FIG. 1A as its light source, such as the box-like luminescent assembly 3 having a plurality of fluorescent lamps 1 arranged at the opening thereof, as shown in FIG. 2, or an arc-shaped luminescent assembly 4 having a fluorescent lamp 1 arranged at the concave of the same, as shown in FIG. 3, all have reflection sheet 5 configured therein for increasing the brightness thereof, all those conventional luminescent assemblies still have poor brightness since the luminous efficacy of the light source employed thereby, i.e. the fluorescent lamps 1, is poor. [0009]A conventional lamp-type white LED is configured, for example, as shown in FIG. 4. That is, in FIG. 4, a white LED includes a pair of lead frames 7 and 8, and a blue LED chip 6 mounted on top of a cup-like base 7' formed on the upper end surface of the lead frame 7, wherein the blue chip 6 is boned to the lead frame 8 by a bonding wire and protected with and package by a fluorescent resin envelop 9, made of a mixture of a filling material and a phosphor capable of emitting a wide range of lights centering around yellow light. Moreover, a light reflecting layer is formed on the inner surface of the cup-like base 7' while surrounding the blue LED chip 6, by which as blue light from the blue LED chip 6 is reflected by the light reflecting layer of the cup-like base 7' and shine on the fluorescent resin envelop 9, the phosphor doped in the fluorescent resin envelop 9 is excited, producing yellow light and externally emitting white light as a result of mixing of the two lights. [0010]Although the aforesaid LED can be considered as a surface-emitting LED, the luminous efficacy is poor since the blue chip 6 is fixedly arranged at the bottom of the cup-like base 7' and the brightness yellow light is excited at the top surface of the LED chip 6 contacting the fluorescent resin envelop 9, so that the brightness of the excited yellow light is decreasing as it is traveling in the fluorescent resin envelop 9 before emitting. SUMMARY OF THE INVENTION [0011]In view of the disadvantages of prior art of poor brightness, the primary object of the present invention is to provide a structure capable of enhancing the brightness of a luminescent assembly by directing blue/ultraviolet light of a light-emitting source to shine on a fluorescent/phosphorescent coating so as to excite visible light therefrom in a surface excitation manner. [0012]To achieve the above object, the invention provide a brightness-enhanced light-emitting structure of a luminescent assembly, comprising: [0013]a light-emitting source, capable of emitting blue/ultraviolet light, having a cover layer formed on a side of the circumference thereof while enabling the cover layer to be composed of a light reflecting layer; and [0014]a light screen, disposed surrounding the light-emitting source, having a primary visible light layer formed at a portion of the inner surface of the light screen at the position corresponding to the side of the light-emitting source where is not covered by the cover layer; [0015]wherein, the primary visible light layer is mainly composed of a fluorescent/phosphorescent coating; and a visible light is emitted from the primary visible light layer in the surface excitation manner as soon as the primary visible light layer is irradiated by the ultraviolet or blue light of the light-emitting source, while the cover layer of the light-emitting source is blocking the harmful ultraviolet light and the same time being excited directly or indirectly to generate another visible light, and thus the brightness of the luminescent assembly is enhanced. [0016]Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS [0017]FIG. 1A and FIG. 1B are schematic diagrams showing the brightness of two conventional fluorescent lamps. [0018]FIG. 2 is a cross sectional view of a box-like luminescent assembly having a plurality of conventional fluorescent lamps arranged at the opening thereof. [0019]FIG. 3 is a cross sectional view of an arc-shaped luminescent assembly having a conventional fluorescent lamp arranged at the concave of the same. [0020]FIG. 4 shows a conventional artillery-shell-shaped light emitting diode. [0021]FIG. 5 is a schematic diagram showing a luminescent assembly according to a first embodiment of the invention. [0022]FIG. 6 is a perspective view illustrating a cross section of a brightness-enhanced light-emitting structure used in the luminescent assembly of the first embodiment of the invention, whereas the cover layer is coated on the inner circumference of the light-emitting source thereof. [0023]FIG. 7 is a cross sectional view of the brightness-enhanced light-emitting structure of FIG. 6 [0024]FIG. 7A is a cross sectional view of the brightness-enhanced light-emitting structure of FIG. 5 having an addition light reflecting layer with a plurality of holes formed on the cover layer thereof. Continue reading... Full patent description for Brightness enhancement structure of luminescent assembly Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Brightness enhancement structure of luminescent assembly patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. 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